Rigid-guide excavator, particularly suitable for the digging of trenches with vertical walls



Mamh 9 3957 FASLLA 33,39,806

RIGID-GUIDE EXCAVATOR, PARTICULARLY SUITABLE FOR THE DIGGING CF TRENCHES WITH VERTICAL WALLS Filed Nov. 18, 1963 I N VENTOR fymzzio 6/7/41.

United States Tatent ()fifice 33%,890 Patented Mar. 21, 1967 3 309,800 RIGID-GUIDE EXCA VA'TOR, PARTHCULARLY SUITABLE FOR THE DIGGING F TRENCHES WITH VERTICAL WALLS Ignazio Faiila, Milan, Italy, assignor to E.L.S.E.S.r.l., Milan, Italy, a company of Italy Filed Nov. 18, 1963, Ser. No. 324,423 Claims priority, application Italy, Nov. 23, 1962, 23,068/ 62 3 Claims. (Cl. 37-103) The present invention relates to an excavator particularly well suited for digging trenches to a considerable depth in hard ground. Excavators of this type generally comprise a base frame to be fixed adjacent the edge of the excavation, a rigid guide member vertically displaceably mounted on said framing base, and a slide member slidable along said rigid guide and carrying hinged to its lower portion an excavating collecting bucket rotatable in the plane of the excavation, the bucket and slide being operated by respective winch means through pulleys mounted at the top end of the rigid guide.

The inventive excavator is characterized in that, between the base framing member and the rigid guide member, there is inserted at least one drive member. The drive members are preferably one or more doubleefiect hydraulic or pneumatic jacks controlled by a special manual distributor. The hydraulic jacks are adopted to cause vertical displacement of the rigid guide member. The jacks are fastened at one end to the base frame and at the other end adjustably fastened to the rigid guide member in successive positions by means arranged in vertical succession on the rigid guide memher at intervals which are spaced apart a distance no greater than the stroke length of the drive members.

In particular, in order to lock the mobile members of the hydraulic jacks to the rigid guide in various positions, there are a number of spaced through holes in the guide member aligned along a vertical axis parallel to that of the guide member. A removable pin means passes through one of said through holes and an eyelet on the movable member of the jacks to'thereby lock the movable member and the guide member at the desired position. A second pin means which is also removable and quite similar to the first pin means is also provided to provisionally fix the rigid guide means to the base framing means when the first pin is being moved from a first position to a subsequent position.

One of the advantages of the rigid guide means with double-eifect drive members is to enable carrying out, in addition to the progressive depth displacement, vertical displacements of the rigid guide independently of the means for controlling the rotation of the bucket and for the lifting of the slide member. Another advantage of the present invention is that of enabling transmission of the pressure exerted by the jacks upon the rigid guide to the teeth of the bucket independently of the rotation of the bucket caused by the rotation control means.

The above features are made possible by the presence of means adapted to lock the slide member on the rigid guide member in register with the lower end of the stroke of said slide member. In particular, there is provided 0n the slide member a movable hook member adapted to engage at the end of its stroke with a fixed projection on the rigid guide member in such a way to render the slide and guide members fixed with each other. The hook is provided with a projection or equivalent member adapted to engage with an arm of the bucket in such a way that the latter in upward rotation disengages the hook from the rigid guide member and therefore permits the free rising of the slide member for bucket discharging operations.

The invention is illustrated for the sake of greater clarity in the accompanying drawings wherein:

FIG. 1 shows diagrammatically a side view of the assembly of the excavator unit;

FIG. 2 shows diagrammatically a front view of a portion of the excavator unit as shown in FIG. 1; and

BIG. 3 is a horizontal section through line IIII1I of FIG. 1.

Referring now to the figures, the rigid guide member 1, having slide member 2 and bucket assembly 3 mounted thereon, is mounted on the base frame 4. Guide arms 5 and 21 projects from the base member 4 to encompass the rigid guide member 1. Double-eifect, operating piston-cylinder assemblies comprise cylinder 22 and operating rod 23. The cylinder 22 is pivotally attached at one end to the guide arms 5. The operating rod 23 has an eyelet 7 at its free end. A plurality of through holes 8 are provided in the rigid guide 1 with the holes having a diameter equal to that of the eyelet 7. Pins 9 are of such diameter as to pass through the holes 8 and eyelet 7 and are of sufiicient length to rest with their projecting ends upon the lower arms 21. A hook member 10 is loosely rotatably pivoted on a pin 12 which also serves as the rotational pivot for the rotary arm 31 of the articulated bucket assembly 3. A stop tooth 11 is rigidly attached to the rigid guide member 1 and is adapted to engage with the book 10. The pin 12 is carried by the slide member 2. The cable 13 serves to actuate the bucket assembly 3. A second cable means 14 serves to actuate the slide member 2.

The piston-cylinder assembly system includes a tank 15 for storing the operating fluid for the operating cylinders 6. The pump 16 serves to pressurize the operating fluid in the system. A pressure gauge 17 is fixed into the fluid lines. A three-position distributor 18 having forward, locked, and backward control positions controls the movement of the operating piston-cylinder assemblies. Pipes 1? and 2t) serve to connect the control unit to the operating piston-cylinder assemblies with the former pipe feeding the top chamber of the operating cylinder and the latter pipe feeding the lower chamber of the operating cylinder.

The operation of the invention is substantially as follows:

The rigid guide member 1 is supported by the pin 9 passing through one of the holes 8 and the eyelet 7 of the cylinder assemblies 6. The operating cylinders are therefore able to displace (within the range of their stroke which at any rate should be larger than the double, inner axial distance between the holes 8) the guide member 1 far enough to bring it into the position indicated in FIG. 1. This serves to start the movement for filling of the bucket assembly. The filling movement is obtained by means of a counterclockwise rotation of the bucket 32 initiated by the action of cable 13 acting between the pulley 24 carried at the end of an arm 33 extending outwardly from the bucket 32 and pulley 25 carried at the upper end of the slide member 2. At the lower end of the rotary arm 31 there is a pivot pin 34 pivotally connecting the rotary arm 31 with the bucket 32. By means of concomitant movements downwards of the pins, rotation of the bucket assembly is controlled. Through the rigid guide member 1 by operation of the distributor 17 regulating the fiow of fluid to the operating cylinder assemblies 6, the vertical movements are controlled by the operator according to the consistency of the ground and the effort to which the teeth 35 of the bucket are subjected. The effort may also be ascertained by reading the pressure gauge 17 since, in the case of excessively growing effort with the rotation of the bucket, the operator can cut off the vertical downward movement, increase the vertical movement, or even reverse it thereby relieving the effort of rotation.

In order to prevent an upward component of the effort exerted by the cable 13, as well as the downward movement transmitted by the rigid guide member 1 controlled by the operating cylinder assemblies 6 to the bucket, from Y displacing the slide member 2 upward with respect to the guide member 1 (before accomplishing the filling rotation), a mobile hook 110 is loosely rotatably mounted on the slide member 2 by means of pin 12. By effect of its own weight when the slide member 2 arrives at its lower end of the stroke with respect to the guide, the hook 10 comes into engagement with the tooth 11 rigid on the guide member 1.

At the end of the filling rotation of the articulated bucket assembly 3, the rotary arm 31 turning about pin 12 comes into contact with a projection, shown schematically at 36, on the mobile hook 10 thus causing it to rotate therewith about the pin 12 to thereby release the projection 11. The release of the hook 10 from the projection 11 permits the slide member 2 to move upward on the guide member 1 by action of the cable 14 to reach the surface of the ground where the bucket may be discharged.

Upon discharge of the bucket at the surface by any conventional means, the slide member is again caused to descend by action of the cable 14 and the concomitant action of the cable 13. The slide member moves downwardly along the rigid guide member 1 until the lower end abuts against the stroke stop 11 and the mobile hook 10 again engages the projection by the effect of its own weight. The mobile hook 10 is designed at its lower end with a cam portion 26 so that at the end of the downward stroke a hooking engagement will be conveniently effected. A contemperaneous movement of reascent of the rigid guide member 1 controlled by operating the cylinder assembly 6, facilitates the clockwise rotation of the bucket which is left free to rotate by its own weight controlled only by the cable 13 until the teeth 35 reach the back edge of the rigid guide member 1 as indicated in FIG. 1. A subsequent movement of descent of the rigid guide member 1 and jointly therewith the bucket assembly 3 is controlled by the operating cylinder assembly 6 to bring the teeth 35 of the bucket to the ground in a position suitable to start a new filling movement according to the method as already set forth.

The repetition of the described excavation steps (descent, filling, ascent, and discharge of the bucket) are accompanied by a gradual penetration of the rigid guide member 1 into the excavation. The penetration is obtained by actuation of the cylinder assemblies 6. When their vertical stroke is exhausted, namely, having reached the extension limit of the rod 23, the rigid guide member 1 is temporaneously suspended by the guard arms 5 and 21 (preferably the lower arm 21) by means of a second pin 9. The first pin 9 is extracted from the eyelet 7 and through holes 8 and the rod 21 is lifted by acting upon the operating cylinders until the eyelet is in register with the next successive hole 8 in a position higher than previously occupied. The eyelets 7 are locked by the first pin 9 to the new hole 8. The assembly is lifted by actuating the operating cylinder assemblies 6 after removing the second pin 9. The previously described excavated operations are then resumed. The possibility of deepening the excavation with a length equal to the interaxial distance between two successive holes 8 being the controlling factor between intermediate depths of the excavation. Upon having carried out the deepening, one proceeds with a moving of the pin 9 to a subsequent hole 8 and so on.

I claim:

1. An excavator particularly for trenches and the like comprising a base frame member, a rigid guide member vertically, displaceably mounted on said base, a slide slidably mounted on the rigid guide member, an excavator collector bucket pivotally mounted on the lower end of said rigid guide member, said 'bucket being pivotal in the plane of the excavation, said bucket and said slide being operated by respective winch means, piston-cylinder means rigidly attached to said base frame member and adjustably connected to said rigid-guide member, manually operated distributor means operatively connected to said piston-cylinder means to cause vertical displacement of said rigid guide member with respect to said baseframe member, said piston cylinder being fixed on one end to the base frame with the movable portion thereof adjustably connected to the rigid guide member so that said guide member and said base member may be ad justed in vertical succession at intervals not greater than the stroke of said piston cylinder, a plurality of holes in succession in said rigid guide member, an eyelet on the end of the movable portion of said piston cylinder arrangement, locking pins for fixedly interconnecting said holes with said eyelet, means for temporarily fixedly attaching said rigid guide means to said base frame during repositioning of the eyelet with respect to said holes.

2. An excavator according to claim 1 in which a hook is pivoted on said slide, a projection on said rigid guide member, said hook engaging with said projection to lock the slide on the rigid guide member at the end of stroke of the slide thereby permitting the pressure exerted by the piston-cylinder means upon said rigid guide to be transmitted to the digging edge of the bucket independent of the force imposed on the bucket by said winch means.

3. An excavator according to claim 2 wherein said hook is provided with a projection adapted to cooperate with a pivotal arm of the bucket in such a way at the end of the active stroke that the hook will disengage from the projection and permit free ascent of the slide and of the bucket for a discharging operation.

References Cited by the Examiner UNITED STATES PATENTS 2,144,246 1/1939 Long 37135 X 2,770,057 11/1956 Camp 37-103 3,021,623 2/1962 Failla 37-103 FOREIGN PATENTS 665,646 1/1952 Great Britain.

ABRAHAM G. STONE, Primary Examiner. WILLIAM A. SMITH III, Examiner. 

1. AN EXCAVATOR PARTICULARLY FOR TRENCHES AND THE LIKE COMPRISING A BASE FRAME MEMBER, A RIGID GUIDE MEMBER VERTICALLY, DISPLACEABLY MOUNTED ON SAID BASE, A SLIDE SLIDABLY MOUNTED ON THE RIGID GUIDE MEMBER, AN EXCAVATOR COLLECTOR BUCKET PIVOTALLY MOUNTED ON THE LOWER END OF SAID RIGID GUIDE MEMBER, SAID BUCKET BEING PIVOTAL IN THE PLANE OF THE EXCAVATION, SAID BUCKET AND SAID SLIDE BEING OPERATED BY RESPECTIVE WINCH MEANS, PISTON-CYLINDER MEANS RIGIDLY ATTACHED TO SAID BASE FRAME MEMBER AND ADJUSTABLY CONNECTED TO SAID RIGID-GUIDE MEMBER, MANUALLY OPERATED DISTRIBUTOR MEANS OPERATIVELY CONNECTED TO SAID PISTON-CYLINDER MEANS TO CAUSE VERTICAL DISPLACEMENT OF SAID RIGID GUIDE MEMBER WITH RESPECT TO SAID BASEFRAME MEMBER, SAID PISTON CYLINDER BEING FIXED ON ONE END TO THE BASE FRAME WITH THE MOVABLE PORTION THEREOF ADJUSTABLY CONNECTED TO THE RIGID GUIDE MEMBER SO THAT SAID GUIDE MEMBER AND SAID BASE MEMBER MAY BE ADJUSTED IN VERTICAL SUCCESSION AT INTERVALS NOT GREATER THAN THE STROKE OF SAID PISTON CYLINDER, A PLURALITY OF HOLES IN SUCCESSION IN SAID RIGID GUIDE MEMBER, AN EYELET ON THE END OF THE MOVABLE PORTION OF SAID PISTON CYLINDER ARRANGEMENT, LOCKING PINS FOR FIXEDLY INTERCONNECTING SAID HOLES WITH SAID EYELET, MEANS FOR TEMPORARILY FIXEDLY ATTACHING SAID RIGID GUIDE MEANS TO SAID BASE FRAME DURING REPOSITIONING OF THE EYELET WITH RESPECT TO SAID HOLES. 